Radius of curvature (R) = 24 cm (negative)
Object distance (u) = 4 cm (negative)
Focal length (f) = 1\over 2 × 24 cm = 12 cm (negative)
Hence, focal length of the concave mirror = -12 cm.
1\over u + 1\over v = 1\over f⇒ –1\over 4 + 1\over v = –1\over 12
⇒ 1\over v = –1\over 12 + 1\over 4
⇒ 1\over v = - 1+3\over 12
⇒ 1\over v = 2\over 12
⇒ 1\over v = 1\over 6
⇒ v = 6 cm
The image is formed 6 cm behind the mirror.
Computing linear magnification:
m = – 6\over -4 = 1.5
As, the length of image is 1.5 times the image of object, hence, the image is magnified.
